As is well known in the art, the suspension of a vehicle comprises a lower arm which is coupled to a knuckle supporting a wheel, and an upper arm which is formed to be positioned above the lower arm and connects the upper portion of the knuckle to a vehicle body to support the knuckle.
The lower arm and the upper arm are fastened to the vehicle body via bushings, and one end of each of the lower and upper arms is coupled to the knuckle by a ball joint.
Depending upon the position of the ball joint, a caster is provided to the wheel. The caster is regarded as an important factor assuring the returnability of the wheel while a vehicle travels on a road.
Meanwhile, if a difference in height exists between the left side and the right side of a vehicle due to the lateral slope of a road on which the vehicle travels, the vehicle leans to one side. This leaning phenomenon of a vehicle serves as a cause of deteriorating the straight-line stability of the vehicle.
The lateral slope of a road, which causes the vehicle to lean, is inevitable due to road conditions.
If the casters of wheels on both sides are properly adjusted, the leaning phenomenon due to the lateral slope of a road can be prevented. However, in view of the existing structures of vehicles, the casters of wheels on both sides cannot be appropriately adjusted while the vehicle is traveling on the road, so it is not possible to actively respond to the leaning phenomenon of the vehicle caused due to the lateral slope of a road.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.